Most understand what we mean when we say “critical path”. To help us keep focused and in context for this blog entry, the critical path describes the longest path in duration that needs to take place, which in tern becomes the minimum time line of a project. To expand the thought a little further, also think about it as a bottleneck in a process causing it to be the critical path.
Lean manufacturing, Kaizen, TPS, look for incremental improvements. It does not really matter what part of the process you apply it to, because your intent is to eliminate waste of all forms and in any process. Most of this is accomplished through observation, or perhaps observation and data. This simplistic concept of incrementally eliminating waste is to sustain the improvement once it is proven and accepted. It takes effort from the team or individual who observed and defined the problem, who gave it proper scope and planning, successfully implementing (the most difficult part), confirming the problem is corrected with any supporting tools in place, making it a Standard. This is the PDSA (plan-do-study-act) cycle (or PDCA for check if you still prefer).
A LinkedIn post (which linked to a presentation) caught my attention and frustrated me when I read it. I jumped to a conclusion that someone was preaching once again “This Is The Way”. I am not too far off in that, and even I can be that way at times in my own preaching. What the reader (meaning you and I) need to remember is the person writing it, whether the post I read or what I write myself, most likely has a target point to make. One that is specific in example and solution, that indeed will work every time or almost every time. Whether we convey it properly in clear thought or writing can be another story.
The presentation I am referring to is titled, “Let’s Retire the PDCA Wedge; What really keeps performance from slipping back?” by Mike Rother and Jeff Uitenbroek, August 2011. The intent (and correct me if I am wrong when you look at the presentation) is that something is throwing a wrench in the works, keeping us from moving forward with continuous improvement. The thought is our definition of a Standard may be the cause. It was also mentioned that no matter how well a Standard is implemented and maintained it will go through entropy (degrade and become a waste of energy).
The presentation then sited some information on Deming’s PDSA, suggesting that the cycle needs to keep turning for never ending improvements. The presentation also mentions Toyota and the difference between Standard and Standardized work. Standard meaning something you want to achieve, and Standardized work as operating as specified by the Standard. It also implies that in “wedge”1 thinking, when we slip backwards we believe we lack discipline and want to blame someone, whereas the Toyota way of thinking recognizes an abnormality that we just have not figured out yet. Sort of like a Kanban being an admittance you do not know how to go 1-piece flow yet.
For me the Deming cycle is about continual improvement. However Deming's focus is generally on reducing process variation. There is not a guarantee you will produce quality. That is dependent upon the how the process was setup and maintained (another form of Standard). There is never a focus on the team member who is willing and able, because we know he cannot affect the output of the process. The process is the process. However continually improving will guarantee uniformity (good or bad) at a low cost.
Toyota has gone to great lengths to specify what they do is Standardized work, and not Standard work. I have gone through Toyota’s supplier training where this was drilled into me. Toyota defines Standardized work as, “. . . organizes all jobs around human motion and creates an efficient production sequence without any “Muda”. Work organized in such a way is called standardized work. It consists of three elements: Takt-Time, Working Sequence, and Standard In-Process Stock.” They went out of their way in class to discourage the use of the word Standard.
I have seen the “wedge” graphic with and without the wedge, and really never put any emphasis on it or used it in my education of others. I do know that when QS-9000 converted over to TS-16949, there was an emphasis to change “continuous improvement” to “continual improvement” (as stated by the AIAG personnel who educated me on TS). The purpose was to get away from the mind set of continuously improving without checking that you sustained first. The graphic was a straight line ramp for continuous improvement vs. a stair step process of continual improvement.
The “wedge” presentation did suggest that one reason we use this mindset is to comply with audits. I would rather hope the audit system changed their process to meet what we need to be doing in our process. The presentation also suggests we do need a Standard in order to satisfy the customer, however the Standard itself will not stop entropy. So the suggestion is, the Standard needs to be a target, a set of conditions to be met in order to satisfy the customer. This is what others and I call “positive tension”. You put enough spring force (improvement) pulling on the PDSA wheel to keep it rolling at a given velocity (so that you do not become cyclical), resulting in it going up the incline indicating continual improvement.
I do agree with the “wedge” presentation that there is never “steady state”, but “constant change”. Whether we like it or not this is very true. However, it is also human nature to not want change, or to view change as a bad thing. To me this is because life, for the most part, moves slowly for us. We do not see the changes per se because it creeps up on us. This gives us time to absorb, condition, and make it a norm or Standard in our lives. Business is different. In the never ending quest to bring in more revenue, to increase margins, we choose to want to do better than the Jones' as it were. If they have it, we want it and we want something better, all to maintain current and to attract new customers. Change is quick, requires thinking, requires revised processes (continual improvement), requires us to work, looking at an ever changing target, rather than taking life slow in increments to yesterday’s Standard.
I do contend that maintaining a Standard will keep the process from slipping back. (Similar to the stair step graphic for TS-16949. Once sustained on the step you do not roll back.) The only entropy taking place should be when the Standard becomes outdated through Kaizen. The high complexity of business makes this so variable that we cannot draw a line in the sand and say “removing the wedge is the way”, or even “using the wedge is the way”. You need to see Your problems and solve Your problems. Can the “wedge” presentation be Your solution? Sure. Can it be the wrong solution? I am just as sure. One application I believe the “wedge” presentation will always work is in marketing. You will need to continually innovate to not only satisfy, but also delight the customer. Where it will not work is automotive Tier 1 supply. Having a Standard (which I should really say "Having Standardized Work") helps maintain a statistically controlled process, and enables you to problem solve when the process becomes out of control and to Kaizen.
I also want to point out you cannot just continually improve willy-nilly. If you do not improve on the critical path, you will not increase the velocity of the process, which is generally where our problems lie. (Will using the Standard as a target necessarily put us on the critical path?) If you incrementally improve, eliminating waste, there is a cost savings and some increase in velocity. What should happen as you continually improve along the non-critical path is that the “bottleneck” in the critical path will expose itself, indicating your next continual improvement event. As you improve you will have a shift in the bottleneck within the processes, and you attack that next. Is the bottleneck always seen? No. Can the bottleneck be calculated? Yes, if you have all the variables. Observation is generally easier because of all the variables. VSM (value stream mapping) also helps to find and see all the variables.
Using the “wedge” can help you determine if you worked on the bottleneck in the process or not. What is your goal, your target? If you stopped to observe the new Standard, has the system improved? Whatever the Standard is, plateau or target condition, it should have removed the problem, satisfying and attracting customers through a system that is aligned to the customer, and through processes that support the system.
So, “This Is The Way” will never work across the board. However you can “Choose Your Path” to make it work. Be specific in your quest to solve a problem. Do not look for the Golden Bee-Bee.
No comments:
Post a Comment